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Auto-thermal reforming (ATR) of acetic acid (HAc) offers a feasible, carbon-neutral way to produce hydrogen, and Ni-based catalysts were found effective in ATR, while catalytic deactivation by sintering and carbon deposition needs to be addressed. Therefore, novel Mn-doped NiTiO3 catalysts were prepared by evaporation induced self-assembly method and tested in ATR; characterizations were used to explore the internal catalytic relationship between the carrier and active metals. The experimental results indicated the NiTiO3 catalyst doped with 10 wt.% of MnO exhibited the highest activity and enhanced stability: the conversion of HAc was stable at 100% and the yield of hydrogen was recorded near 2.5 mol-H2/mol-HAc. The characterization results showed that the NiTiO3 catalyst presented the highest specific surface area at 7.5 m2/g. After reduction and activation, NiTiO3 was transformed into Ni0, while Mn replaced Ni in NiTiO3 and formed a stable phase of MnTiO3 perovskite, which presented confinement effect on Ni0, preventing migration of Ni0 at high temperature with a relatively stable particle size within 41.6-44.5nm. These MnTiO3-supported nickel species effectively promoted the conversion of intermediate products such as CH3CO*, inhibited carbon deposition and improved hydrogen selectivity, showing application potential for hydrogen production via ATR of HAc. [ABSTRACT FROM AUTHOR]

Hydrogen, as a promising energy carrier, can be extracted from renewable biomass derived acetic acid (HAc). Ni-based catalysts supported on solid solution of Sm2−xPrxO3±δ were prepared using a coprecipitation method and evaluated in auto-thermal reforming (ATR) of HAc for hydrogen production. The results revealed that Pr species infiltrated the Sm2O3 lattice and formed a solid solution structure with oxygen vacancy defects, in which the redox process of Sm3+ + Pr3+ Sm2+ + Pr4+ enhanced oxygen mobility, facilitating gasification of the coking precursor and suppressing carbon deposition. DFT analysis also confirmed that Pr doping into the Sm2−xPrxO3±δ solid solution significantly lowered the energy barrier by 112 kJ mol−1 for formation of oxygen vacancies. Additionally, the interaction between Ni0 and Sm2−xPrxO3±δ effectively improved the dispersion of Ni0 metal particles, inhibiting sintering of Ni species. Consequently, the NSP10 catalyst (Ni0.80Sm1.72Pr0.24O3.74±δ) exhibited outstanding catalytic performance for hydrogen production: the conversion of HAc approached 100%, while the hydrogen yield remained stable at 2.75 mol-H2/mol-HAc. [ABSTRACT FROM AUTHOR]

To obtain high yields of hydrogen, a series of ZrxPr1–xOy‐supported cobalt catalysts were synthesized by the sol‐gel method and tested in autothermal reforming (ATR) of acetic acid (HAc) derived from bio‐oil. X‐ray diffraction, nitrogen physisorption, H2‐temperature‐programmed reduction, and thermogravimetric analysis were conducted to investigate the factors affecting the activities of the catalysts. Over the Co‐Zr‐Pr‐O catalyst, a ZrxPr1–xOy solid solution was formed after calcination; meanwhile, the active component of Co0 was highly dispersed over the solid solution after reduction in hydrogen for 1 h at 700 °C. As a result, stable reactivity was recorded in the ATR process of HAc: the hydrogen yield reached 2.58 molH2molHAc-1 with near 100 % HAc conversion, while better resistance to coking was observed. [ABSTRACT FROM AUTHOR]

Nickel-based catalysts are widely applied in auto-thermal reforming (ATR) of acetic acid (HAc) to extract hydrogen, but the persistent issue of coking is still a concern. Herein, Ce 1-x Y x O 2-δ solid solutions were obtained to support nickel and the catalytic activity for the ATR was examined. The results indicated that with Y species in CeO 2 lattice, the Ce 1-x Y x O 2-δ solid solution structures with lattice defects and cell dislocation were formed; Meanwhile, the strong nickel-support interaction effectively constrained aggregation of Ni0; In addition, the solid solution induced formation of oxygen vacancies, and facilitated transfer and activation of oxygen species (O*). The DFT analysis further evidences the lower formation energy of oxygen vacancy over the solid solution. Therefore, the optimized Ni 0.8 Ce 1.76 Y 0.35 O 4.85 ±δ catalyst provided excellent stability for activity test (50 h), in which HAc conversion and H 2 yield stabilized at 100% and 2.6 mol-H 2 /mol-HAc, respectively, without obvious coking. [Display omitted] • Solid solution Ce 1-x Y x O 2-δ nickel-based catalysts were synthesized by sol-gel. • Lattice defects and cell dislocation were caused by Y atom insertion. • Y doping enhanced resistance to carbon deposition of nickel-based catalyst. • Ni 0.8 Ce 1.76 Y 0.35 O 4.85 ±δ catalyst shows better performance for ATR of acetic acid. • DFT shows that Y doping decreases the formation energy of oxygen vacancy. [ABSTRACT FROM AUTHOR]